Bitcoin is a commodity, not a currency. People forget that.
There is a finite number of bitcoins that can be mined (21 million). Nerds around the globe are using their computers to solve complex math problems to “find” (mine) the correct “code” (block) Once a block is found it is offered up for everyone else to validate. Then the finder is rewarded with 25 bitcoins (current bounty) and that code is added to the blockchain, which serves as a record of all bitcoin mining.
The difficulty of the mining readjusts after every 2016 blocks are mined. The diffculity is reset so that it will take 2 weeks to mine the next 2016 blocks based on the amount of miners/effort that attempted to mine the previous 2016 blocks.
Please excuse me as I have to make sure some sidewalks slope at no less than 2% for storm drainage purposes and not more than 2% for wheelchair accessibility purposes, thanks.